- replace deprecated is_a() calls with instanceof operator # unittests still pass
- replace deprecated is_a() calls with instanceof operator
# unittests still pass

git-svn-id: 526f3b90ad6d9b1dfe840af828070ca3d99521ac@9305 d2cacbed-c0f6-0310-851a-9dad52fc623a

johannes85/core